The present invention relates to an inverse dispersion comprising at least one cationic polymer and at least one stabilizing agent, wherein the stabilizing agent has one or more hydrophobic chains with more than 50 carbon atoms. The polymer is obtainable by polymerizing at least one cationic monomer and optionally at least one nonionic monomer. Furthermore, the present invention relates to a process for manufacturing the inverse dispersion by inverse emulsion polymerization.
WO03/102043 describes an aqueous formulation comprising a cationic polymer having: a) a water soluble ethylenically unsaturated monomer or blend of monomers comprising at least one cationic monomer; b) at least one cross-linking agent in an amount of more than 50 ppm by the weight of component a); c) and at least one chain transfer agent. The aqueous formulations can be used as thickeners in home care formulations.
EP 1 756 168 discloses spherical microparticles of hydrophilic acrylic polymers, whether anionic or cationic in charge, which have a typical particle size in the range of 0.1-2 microns, with an average particle size in the range of 0.5-1 micron. The polymeric microparticles are preferably manufactured by methods in which water-soluble vinyl addition monomers are polymerized utilizing a water-in-oil polymerization route. On stirring of any of the above liquid dispersion polymers into an aqueous system, the activator surfactant converts the hydrophobic carrier into an oil-in-water emulsion. By the term “activator surfactant” is meant a surfactant that activates the conversion of the hydrophobic carrier into an oil-in-water emulsion. At the same time the hydrophilic polymer expands on exposure to water but does not dissolve, resulting in a smooth and rapid viscosity increase. Typically the polymer particles swell to give a microparticulate thickening system comprising polymer particles having a typical particle size in the range of 2.5-5 microns in diameter. Since the water molecules move into the small polymer particles by osmosis, the osmotic effect experienced by the polymer particle is a balance between water and any electrolyte present in the system. Hence high electrolyte levels reduce the swelling of the polymer particles.
WO 2009/019225 reads on an aqueous dispersion of an alkali-soluble copolymer, said dispersion being suitable as an associative thickener. The copolymer comprises polymerized units of a) at least one ethylenically unsaturated carboxylic acid, b) at least one nonionic ethylenically unsaturated surfactant monomer, c) at least one C1-C2-alkyl methacrylate and d) at least one C2-C4-alkyl acrylate, where the alkyl chain length averaged over the number of alkyl groups of the alkyl acrylate is 2.1 to 4.0. The associative thickeners can be prepared by emulsion polymerization and are suitable for use in washing and cleaning compositions.
WO 2010/078959 relates to cationic polymer thickeners consisting of a crosslinked water-swellable cationic polymer comprising at least one cationic monomer and optionally nonionic or anionic monomers, said polymer comprising less than 25% of water-soluble polymer chains, based on the total weight of the polymer. The polymer also comprises a crosslinker in a concentration of 500 to 5000 ppm relative to the polymer. The cationic polymer is prepared by inverse emulsion polymerization.
WO 2010/079100 discloses fabric softener compositions comprising polymers according to WO 2010/078959.
US 2008/0312343 reads on inverse latex compositions and to the use thereof as a thickener and/or emulsifier, for example for production of cosmetic or pharmaceutical formulations. The inverse latex compositions comprise at least 50 to 80% by weight of at least one linear, branched or crosslinked organic polymer (P), at least 5 to 10% by weight of a water-in-oil-type emulsifier system, 5 to 45% by weight of at least one oil and up to 5% water. The polymer P comprises uncharged monomers and optionally cationic or anionic monomers. The inverse latex composition may optionally comprise up to 5% by weight of an oil-in-water-type emulsifier system. The inverse latex compositions can be prepared by inverse emulsion polymerization.
EP-A 172 025 relates to a dispersion in a continuous liquid phase of a polymer, which is formed by polymerization of an ethylenically unsaturated monomer comprising a hydrophobic group of at least eight carbon atoms and an ethylenically unsaturated monomer copolymerizable therewith. The dispersion is stable and essentially anhydrous, and comprises at least 40% by weight of polymer. In the polymerization, the copolymerizable, ethylenically unsaturated monomers used may, for example, be anionic monomers. The polymerization can be performed as an inverse emulsion polymerization.
EP-A 172 724 relates to polymers which are prepared by copolymerization of a) an ethylenically unsaturated monomer comprising a hydrophobic group with at least eight carbon atoms and b) water-soluble ethylenically unsaturated monomers. All monomers are soluble as a mixture in water, and the polymer is prepared by inverse emulsion polymerization. The polymer particles have a dry size of <4 μm. The monomer components b) used may be anionic monomers such as acrylic acid in the form of the free acid or as a water-soluble salt, and nonionic monomers such as acrylamide.
EP-A 172 723 describes a process for flocculating a suspension using a water-soluble, essentially linear polymer with a “single point intrinsic viscosity” of >3. The polymer is a copolymer of two or more ethylenically unsaturated monomers comprising at least 0.5% by weight of a monomer, comprising hydrophobic groups. The polymer may also be a cationic polymer.